(In reply to Yves W. from comment #38)
> means i have to try manually each step and recompile kernel? But that will
> take ages :) I don't have that much time.

No git bisect will do this automatically for you.

Additional to that you don't need to compile every commit in the range. It
simply does a binary search, reducing the number of compiles to something close
to square root of the number of commits.

That's usually quite handleable.